Protein composition and its use in restructured meat and food products

ABSTRACT

The invention provides protein compositions containing structured protein products having protein fibers that are substantially aligned.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 11/437,164,filed on May 19, 2006.

FIELD OF THE INVENTION

The present invention provides a protein composition and the use of theprotein composition in vegetable products, fruit products, and inrestructured meat products. The invention further provides a process forpreparing the hydrated and shredded protein composition.

BACKGROUND OF THE INVENTION

An important aspect of the present invention is the development of anunstructured protein product into a structured protein product.Particularly, in one embodiment, the present invention provides aproduct and method for taking an unstructurized protein product with novisible grain or texture and converting it into a structurized, proteinproduct with a definite shape having the consistency of cooked musclemeat.

The term “structure” describes a wide variety of physical properties ofa food product. A product of acceptable structure is usually synonymouswith the quality of a product. Structure has been defined as “theattribute of a substance resulting from a combination of physicalproperties and perceived by senses of touch, including kinethesia andmouth feel, sight, and hearing. Structure, as defined by theInternational Organization of Standardization, is “all of therheological and structural (geometric and surface) attributes of a foodproduct perceptible by means of mechanical, tactual and, whereappropriate, visual and auditory receptors.” The following terms havebeen used to describe product characteristics falling under the umbrella“structure”:

TABLE I ABRIDGED LIST OF FOOD STRUCTURE ADJECTIVES Adhesive BouncyBrittle Bubbly Chewy Clingy Coating Cohesive Creamy Crisp Crumbly CrustyDense Doughy Dry Elastic Fatty Firm Flaky Fleshy Fluffy Foamy FragileFull-bodied Gooey Grainy Gritty Gummy Hard Heavy Heterogeneous JuicyLean Light Limp Lumpy Moist Mouth coating Mushy Oily Pasty PlasticPorous Powdery Puffy Pulpy Rich Rough Rubbery Runny Sandy Scratchy ShortSilky Slippery Slivery Smooth Soft Soggy Sparkly Splintery SpongySpringy Sticky Stringy Syrupy Tender Thick Thin Tingly Tough UniformViscous Watery Waxy Wiggly

Accelerated attention has been given to structure as it pertains tonewer food substances including fabricated and imitation products,formed meat and fish products, where very serious efforts are made byprocesses to duplicate the properties of the original or other naturalfood substances. The use of non-traditional raw materials, syntheticflavors, fillers, stretchers, and extenders all tend to alter certaintextural characteristics of the finished product. Frequently, theimitation of textural properties is of much greater difficulty in thereplication of taste, odors, and colors. Numerous manipulativeprocesses, including extrusion structurization, have been developed tosimulate natural structural properties. The processes generally find itprudent to duplicate the properties of the original substances to theextent feasible technically and economically in order to promote earlymarket acceptance. While structure has attributes related to appearance,it also has attributes related to touch and also mouth feel orinteraction of food when it comes in contact with the mouth. Frequently,these sensory perceptions involved with chewing can relate toimpressions of either desirability or undesirability.

Thus, structural terms include terms relating to the behavior of thematerial under stress or strain and include, for example, the following:firm, hard, soft, tough, tender, chewy, rubbery, elastic, plastic,sticky, adhesive, tacky, crispy, crunchy, etc. Secondly, structure termsmay be related to the structure of the material: smooth, fine, powdery,chalky, lumpy, mealy, coarse, gritty, etc. Third, structure terms mayrelate to the shape and arrangement of structural elements, such as:flaky, fibrous, stringy, pulpy, cellular, crystalline, glassy, spongy,etc. Last, structure terms may relate to mouth feel characteristics,including: mouth feel, body, dry, moist, wet, watery, waxy, slimy,mushy, etc.

As used herein, “unstructurized” and “structurized” describe thecharacteristics of the food product as set forth in Table II:

TABLE II Unstructurized Structurized Characteristic CharacteristicBehavior of sticky firm Material under gooey chewy Stress or Strainplastic Structure of smooth coarse Material Shape and gelatinous fibrousArrangement of pulpy crusty Structural Elements pasty Mouth Feel Creamymoist mushy dry with body

SUMMARY OF THE INVENTION

One aspect of the invention provides a process for producing arestructured meat composition. The process generally comprises:extruding a plant protein material under conditions of elevatedtemperature and pressure through a die assembly to form a structuredplant protein product having protein fibers that are substantiallyaligned.

Another aspect of the invention provides a restructured meatcomposition. The restructured meat composition comprising a structuredprotein product having protein fibers that are substantially aligned.

FIGURE LEGENDS

FIG. 1 depicts a photographic image of a micrograph showing a structuredplant protein product of the invention having protein fibers that aresubstantially aligned.

FIG. 2 depicts a photographic image of a micrograph showing a plantprotein product not produced by the process of the present invention.The protein fibers comprising the plant protein product, as describedherein, are crosshatched.

FIG. 3 depicts a perspective view of a peripheral die assembly that maybe used in the extrusion process of the protein containing materials.

FIG. 4 depicts an exploded view of the peripheral die assembly of FIG. 3showing the die insert, die sleeve and die cone.

FIG. 5 depicts a cross-sectional view taken along line 9-9 of FIG. 3showing a flow channel defined between the die sleeve, die insert, anddie cone arrangement.

FIG. 5A depicts an enlarged cross-sectional view of FIG. 5 showing theinterface between the flow channel and the outlet of the die sleeve.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides hydrated and shredded proteincompositions and processes for producing each of the compositions.Typically, the protein composition will comprise animal meat andstructured protein products having protein fibers that are substantiallyaligned. Alternatively, the protein composition will comprise acomminuted vegetable or comminuted fruit and structured protein productshaving protein fibers that are substantially aligned.

(I) Structured Protein Products

The protein compositions of the invention each comprise structuredprotein products comprising protein fibers that are substantiallyaligned, as described in more detail in I(e) below. In an exemplaryembodiment, the structured protein products are extrudates of proteinmaterial that have been subjected to the extrusion process detailed inI(d) below. Because the structured protein products have protein fibersthat are substantially aligned in a manner similar to animal meat, theprotein compositions of the invention generally have the texture andeating quality characteristics of compositions comprised of one hundredpercent animal meat.

(a) Protein-Containing Materials

A variety of ingredients that contain protein may be utilized in athermal plastic extrusion process to produce structured protein productssuitable for use in the protein compositions herein. While ingredientscomprising proteins derived from plants are typically used, it is alsoenvisioned that proteins derived from other sources, such as animalsources, may be utilized without departing from the scope of theinvention. For example, a dairy protein selected from the groupconsisting of casein, caseinates, whey protein, and mixtures thereof maybe utilized. In an exemplary embodiment, the dairy protein is wheyprotein. By way of further example, an egg protein selected from thegroup consisting of ovalbumin, ovoglobulin, ovomucin, ovomucoid,ovotransferrin, ovovitella, ovovitellin, albumin globulin, and vitellinmay be utilized. Further, meat proteins or protein ingredientsconsisting of collagen, blood, organ meat, mechanically separated meat,partially defatted tissue and blood serum proteins may be included asone or more of the ingredients of the structured protein products.

It is envisioned that other ingredient types in addition to proteins maybe utilized. Non-limiting examples of such ingredients include sugars,starches, oligosaccharides, soy fiber and other dietary fibers.

It is also envisioned that the protein-containing materials may begluten-free. Because gluten is typically used in filament formationduring the extrusion process, if a gluten-free starting material isused, an edible cross-linking agent may be utilized to facilitatefilament formation. Non-limiting examples of suitable cross-linkingagents include Konjac glucomannan (KGM) flour, beta 1,3 glucan(Pureglucan™ or Curdlan manufactured by Takeda-Kirin Foods),transglutaminase, calcium salts, and magnesium salts. One skilled in theart can readily determine the amount of cross-linking material needed,if any, in gluten-free embodiments.

Irrespective of its source or ingredient classification, the ingredientsutilized in the extrusion process are typically capable of formingextrudates having protein fibers that are substantially aligned.Suitable examples of such ingredients are detailed more fully below.

(i) Plant Protein Materials

In an exemplary embodiment, at least one ingredient derived from a plantwill be utilized to form the protein-containing materials. Generallyspeaking, the ingredient will comprise a protein. The amount of proteinpresent in the ingredient(s) utilized can and will vary depending uponthe application. For example, the amount of protein present in theingredient(s) utilized may range from about 40% to about 100% by weight.In another embodiment, the amount of protein present in theingredient(s) utilized may range from about 50% to about 100% by weight.In an additional embodiment, the amount of protein present in theingredient(s) utilized may range from about 60% to about 100% by weight.In a further embodiment, the amount of protein present in theingredient(s) utilized may range from about 70% to about 100% by weight.In still another embodiment, the amount of protein present in theingredient(s) utilized may range from about 80% to about 100% by weight.In a further embodiment, the amount of protein present in theingredient(s) utilized may range from about 90% to about 100% by weight.

The ingredient(s) utilized in extrusion may be derived from a variety ofsuitable plants. By way of non-limiting example, suitable plants includelegumes, corn, peas, canola, sunflowers, sorghum, rice, amaranth,potato, tapioca, arrowroot, canna, lupin, rape, wheat, oats, rye,barley, and mixtures thereof.

In one embodiment, the ingredients are isolated from wheat and soybeans.In another exemplary embodiment, the ingredients are isolated fromsoybeans. Suitable wheat derived protein-containing ingredients includewheat gluten, wheat flour, and mixtures thereof. Examples ofcommercially available wheat gluten that may be utilized in theinvention include Gem of the Star Gluten, Vital Wheat Gluten (organic)each of which is available from Manildra Milling. Suitable soybeanderived protein-containing ingredients (“soy protein material”) includesoybean protein isolate, soy protein concentrate, soy flour, andmixtures thereof, each of which are detailed below. Suitable cornderived protein-containing ingredients include corn gluten meal, forexample, zein. In each of the foregoing embodiments, the soybeanmaterial may be combined with one or more ingredients selected from thegroup consisting of a starch, flour, gluten, a dietary fiber, andmixtures thereof.

Suitable examples of protein-containing material isolated from a varietyof sources are detailed in Table III, which shows various combinations.

TABLE III Protein Combinations First Protein Source Second Ingredientsoybean wheat soybean dairy soybean egg soybean corn soybean ricesoybean barley soybean sorghum soybean oat soybean millet soybean ryesoybean triticale soybean buckwheat soybean pea soybean peanut soybeanlentil soybean lupin soybean channa(garbonzo) soybean rapeseed (canola)soybean cassava soybean sunflower soybean whey soybean tapioca soybeanarrowroot soybean amaranth soybean wheat and dairy soybean wheat and eggsoybean wheat and corn soybean wheat and rice soybean wheat and barleysoybean wheat and sorghum soybean wheat and oat soybean wheat and milletsoybean wheat and rye soybean wheat and triticale soybean wheat andbuckwheat soybean wheat and pea soybean wheat and peanut soybean wheatand lentil soybean wheat and lupin soybean wheat and channa (garbonzo)sovbean wheat and rapeseed (canola) soybean wheat and cassava soybeanwheat and sunflower soybean wheat and potato soybean wheat and tapiocasoybean wheat and arrowroot soybean wheat and amaranth soybean corn andwheat soybean corn and dairy soybean corn and egg soybean corn and ricesoybean corn and barley soybean corn and sorghum soybean corn and oatsoybean corn and millet soybean corn and rye soybean corn and triticalesoybean corn and buckwheat soybean corn and pea soybean corn and peanutsoybean corn and lentil soybean corn and lupin soybean corn and channa(garbonzo) soybean corn and rapeseed (canola) soybean corn and cassavasoybean corn and sunflower soybean corn and potato soybean corn andtapioca soybean corn and arrowroot soybean corn and amaranth

In each of the embodiments delineated in Table III, the combination ofprotein-containing materials may be combined with one or moreingredients selected from the group consisting of a starch, flour,gluten, a dietary fiber, and mixtures thereof. In one embodiment, theprotein-containing material comprises protein, starch, gluten, andfiber. In an exemplary embodiment, the protein-containing materialcomprises from about 45% to about 65% soy protein on a dry matter basis;from about 20% to about 30% wheat gluten on a dry matter basis; fromabout 10% to about 15% wheat starch on a dry matter basis; and fromabout 1% to about 5% fiber on a dry matter basis. In each of theforegoing embodiments, the protein-containing material may comprisedicalcium phosphate, L-cysteine or combinations of both dicalciumphosphate and L-cysteine.

(ii). Soy Protein Materials

In an exemplary embodiment, as detailed above, soy protein isolate, soyprotein concentrate, soy flour, and mixtures thereof may be utilized inthe extrusion process. The soy protein materials may be derived fromwhole soybeans in accordance with methods generally known in the art.The whole soybean may be standard soybeans (i.e., non geneticallymodified soybeans), commoditized soybeans, genetically modifiedsoybeans, and combinations thereof.

Generally speaking, when soy isolate is used, an isolate is preferablyselected that is not a highly hydrolyzed soy protein isolate. In certainembodiments, highly hydrolyzed soy protein isolates, however, may beused in combination with other soy protein isolates provided that thehighly hydrolyzed soy protein isolate content of the combined soyprotein isolates is generally less than about 40% of the combined soyprotein isolates, by weight. Additionally, the soy protein isolateutilized preferably has an emulsion strength and gel strength sufficientto enable the protein in the isolate to form fibers that aresubstantially aligned upon extrusion. Examples of soy protein isolatesthat are useful in the present invention are commercially available, forexample, from Solae, LLC (St. Louis, Mo.), and include SUPRO® 500E,SUPRO® EX 33, SUPRO® 620, SUPRO® 630, and SUPRO® 545. In an exemplaryembodiment, a form of SUPRO® 620 is utilized as detailed in Example 3.

Alternatively, soy protein concentrate may be blended with the soyprotein isolate to substitute for a portion of the soy protein isolateas a source of soy protein material. Typically, if a soy proteinconcentrate is substituted for a portion of the soy protein isolate, thesoy protein concentrate is substituted for up to about 40% of the soyprotein isolate by weight, at most, and more preferably is substitutedfor up to about 30% of the soy protein isolate by weight. Examples ofsuitable soy protein concentrates useful in the invention includePromine DSPC, Procon, Alpha 12 and Alpha 5800, which are commerciallyavailable from Solae, LLC (St. Louis, Mo.).

Soy cotyledon fiber may optionally be utilized as a fiber source.Typically, suitable soy cotyledon fiber will generally effectively bindwater when the mixture of soy protein and soy cotyledon fiber isco-extruded. In this context, “effectively bind water” generally meansthat the soy cotyledon fiber has a water holding capacity of at least5.0 to about 8.0 grams of water per gram of soy cotyledon fiber, andpreferably the soy cotyledon fiber has a water holding capacity of atleast about 6.0 to about 8.0 grams of water per gram of soy cotyledonfiber. Soy cotyledon fiber may generally be present in the soy proteinmaterial in an amount ranging from about 1% to about 20%, preferablyfrom about 1.5% to about 20% and most preferably, at from about 2% toabout 5% by weight on a moisture free basis. Suitable soy cotyledonfiber is commercially available. For example, FIBRIM® 1260 and FIBRIM®2000 are soy cotyledon fiber materials that are commercially availablefrom Solae, LLC (St. Louis, Mo.).

(b) Additional Ingredients

A variety of additional ingredients may be added to any of theprotein-containing materials detailed above without departing from thescope of the invention. For example, antioxidants, antimicrobial agents,and combinations thereof may be included. Antioxidant additives includeBHA, BHT, TBHQ, vitamins A, C and E and derivatives thereof.Additionally, various plant extracts such as those containingcarotenoids, tocopherols or flavonoids having antioxidant properties,may be included to increase the shelf-life or nutritionally enhance theprotein compositions. The antioxidants and the antimicrobial agents mayhave a combined presence at levels of from about 0.01% to about 10%,preferably, from about 0.05% to about 5%, and more preferably from about0.1% to about 2%, by weight of the protein-containing materials.

(c) Moisture Content

As will be appreciated by the skilled artisan, the moisture content ofthe protein-containing materials and optional additional ingredients canand will vary. The purpose of the water is to hydrate the ingredients ofthe protein composition. Generally speaking, the moisture content mayrange from about 1% to about 80% by weight. In low moisture extrusionapplications, the moisture content of the protein-containing materialsmay range from about 1% to about 35% by weight. Alternatively, in highmoisture extrusion applications, the moisture content of theprotein-containing materials may range from about 35% to about 80% byweight. In an exemplary embodiment, the extrusion application utilizedto form the extrudates is low moisture. An exemplary example of a lowmoisture extrusion process to produce extrudates having proteins withfibers that are substantially aligned is detailed in I(d) and Example 3.

(d) Extrusion of the Protein-Containing Material

A suitable extrusion process for the preparation of structured proteinproducts comprises introducing the protein material, and otheringredients into a mixing vessel (i.e., an ingredient blender) tocombine the ingredients and form a dry blended protein material pre-mix.The dry blended protein material pre-mix may be transferred to a hopperfrom which the dry blended ingredients are introduced along withmoisture into a pre-conditioner to form a conditioned protein materialmixture. The conditioned material is then fed to an extruder in whichthe mixture is heated under mechanical pressure generated by the screwsof the extruder to form a molten extrusion mass. Alternatively, the dryblended protein material pre-mix may be directly fed to an extruder inwhich moisture and heat are introduced to form a molten extrusion mass.The molten extrusion mass exits the extruder through an extrusion dieassembly forming an extrudate comprising structured protein productshaving protein fibers that are substantially aligned.

(i) Extrusion Process Conditions

Among the suitable extrusion apparatuses useful in the practice of thepresent invention is a double barrel, twin-screw extruder as described,for example, in U.S. Pat. No. 4,600,311. Further examples of suitablecommercially available extrusion apparatuses include a CLEXTRAL ModelBC-72 extruder manufactured by Clextral, Inc. (Tampa, Fla.); a WENGERModel TX-57 extruder, a WENGER Model TX-168 extruder, and a WENGER ModelTX-52 extruder all manufactured by Wenger Manufacturing, Inc. (Sabetha,Kans.). Other conventional extruders suitable for use in this inventionare described, for example, in U.S. Pat. Nos. 4,763,569, 4,118,164, and3,117,006, which are hereby incorporated by reference in their entirety.

The screws of a twin-screw extruder can rotate within the barrel in thesame or opposite directions. Rotation of the screws in the samedirection is referred to as single flow whereas rotation of the screwsin opposite directions is referred to as double flow. The speed of thescrew or screws of the extruder may vary depending on the particularapparatus; however, it is typically from about 250 to about 400revolutions per minute (rpm). Generally, as the screw speed increases,the density of the extrudate will decrease. The extrusion apparatuscontains screws assembled from shafts and worm segments, as well asmixing lobe and ring-type shearlock elements as recommended by theextrusion apparatus manufacturer for extruding plant protein material.

The extrusion apparatus generally comprises a plurality of temperaturecontrolled zones through which the protein mixture is conveyed undermechanical pressure prior to exiting the extrusion apparatus through anextrusion die assembly. The temperature in each successive heating zonegenerally exceeds the temperature of the previous heating zone bybetween about 10° C. and about 70° C. In one embodiment, the conditionedpre-mix is transferred through four heating zones within the extrusionapparatus, with the protein mixture heated to a temperature of fromabout 100° C. to about 150° C. such that the molten extrusion massenters the extrusion die assembly at a temperature of from about 100° C.to about 150° C.

The barrel pressure is dependent on numerous factors including, forexample, the extruder screw speed, feed rate of the mixture to thebarrel, feed rate of water to the barrel, and the viscosity of themolten mass within the barrel.

Water may be injected into the extruder barrel to hydrate the plantprotein material mixture and promote texturization of the proteins. Asan aid in forming the molten extrusion mass, the water may act as aplasticizing agent. Water may be introduced to the extruder barrel viaone or more injection jets in communication with a heating zone.Typically, the mixture in the barrel contains from about 1% to about 30%by weight water. In one embodiment, the mixture in the barrel containsfrom about 5% to about 20% by weight water. The rate of introduction ofwater to any of the heating zones is generally controlled to promoteproduction of an extrudate having desired characteristics. It has beenobserved that as the rate of introduction of water to the barreldecreases, the density of the extrudate decreases.

(ii) Optional Preconditioning

In a pre-conditioner, the protein-containing material and optionaladditional ingredients (protein-containing mixture) are preheated,contacted with moisture, and held under temperature and pressureconditions to allow the moisture to penetrate and soften the individualparticles. The preconditioning step increases the bulk density of theparticulate fibrous material mixture and improves its flowcharacteristics. The preconditioner contains one or more paddles topromote uniform mixing of the protein and transfer of the proteinmixture through the preconditioner. The configuration and rotationalspeed of the paddles vary widely, depending on the capacity of thepreconditioner, the extruder throughput and/or the desired residencetime of the mixture in the preconditioner or extruder barrel. Generally,the speed of the paddles is from about 500 to about 1300 revolutions perminute (rpm).

Typically, the protein-containing mixture is pre-conditioned prior tointroduction into the extrusion apparatus by contacting the pre-mix withmoisture (i.e., steam and/or water). Preferably the protein-containingmixture is heated to a temperature of from about 20° C. to about 60° C.,more preferably from about 30° C. to about 45° C. in the preconditioner.

Typically, the protein-containing pre-mix is conditioned for a period ofabout 0.5 minutes to about 10.0 minutes, depending on the speed and thesize of the pre-conditioner. In an exemplary embodiment, theprotein-containing pre-mix is conditioned for a period of about 3.0minutes to about 5.0 minutes. The pre-mix is contacted with steam and/orwater and heated in the pre-conditioner at generally constant steam flowto achieve the desired temperatures. The water and/or steam conditions(i.e., hydrates) the pre-mix, increases its density, and facilitates theflowability of the dried mix without interference prior to introductionto the extruder barrel where the proteins are texturized. If lowmoisture pre-mix is desired, the conditioned pre-mix may contain fromabout 1% to about 35% (by weight) water. If high moisture pre-mix isdesired, the conditioned pre-mix may contain from about 35% to about 80%(by weight) water.

The conditioned pre-mix typically has a bulk density of from about 0.25g/cm³ to about 0.60 g/cm³. Generally, as the bulk density of thepre-conditioned protein mixture increases within this range, the proteinmixture is easier to process. This is presently believed to be due tosuch mixtures occupying all or a majority of the space between thescrews of the extruder, thereby facilitating conveying the extrusionmass through the barrel.

(iii) Extrusion Process

The dry pre-mix or the conditioned pre-mix is then fed into an extruderto heat, shear, and ultimately plasticize the mixture. The extruder maybe selected from any commercially available extruder and may be a singlescrew extruder or preferably a twin-screw extruder that mechanicallyshears the mixture with the screw elements.

The rate at which the pre-mix is generally introduced to the extrusionapparatus will vary depending upon the particular apparatus. Generally,the pre-mix is introduced at a rate of no more than about 25 kilogramsper minute. Generally, it has been observed that the density of theextrudate decreases as the feed rate of pre-mix to the extruderincreases.

The pre-mix is subjected to shear and pressure by the extruder toplasticize the mixture. The screw elements of the extruder shear themixture as well as create pressure in the extruder by forcing themixture forwards though the extruder and through the die assembly. Thescrew motor speed determines the amount of shear and pressure applied tothe mixture by the screw(s). Preferably, the screw motor speed is set toa speed of from about 200 rpm to about 500 rpm, and more preferably fromabout 300 rpm to about 400 rpm, which moves the mixture through theextruder at a rate of at least about 20 kilograms per hour and morepreferably at least about 40 kilograms per hour. Preferably the extrudergenerates an extruder barrel exit pressure of from about 500 to about1500 psig, and more preferably an extruder barrel exit pressure of fromabout 600 to about 1000 psig is generated.

The extruder heats the mixture as it passes through the extruderdenaturing the protein in the mixture. The extruder includes a means forheating and/or cooling the mixture to temperatures of from about 100° C.to about 180° C. Preferably, the means for heating or cooling themixture in the extruder comprises extruder barrel jackets into whichheating or cooling media such as steam or water may be introduced tocontrol the temperature of the mixture passing through the extruder. Theextruder may also include steam injection ports for directly injectingsteam into the mixture within the extruder. The extruder preferablyincludes multiple heating zones that can be controlled to independenttemperatures, where the temperatures of the heating zones are preferablyset to increase the temperature of the mixture as it proceeds throughthe extruder. In one embodiment, the extruder may be set in a fourtemperature zone arrangement, where the first zone (adjacent theextruder inlet port) is set to a temperature of from about 80° C. toabout 100° C., the second zone is set to a temperature of from about100° C. to 135° C., the third zone is set to a temperature of from 135°C. to about 150° C., and the fourth zone (adjacent the extruder exitport) is set to a temperature of from 150° C. to 180° C. The extrudermay be set in other temperature zone arrangements, as desired. Inanother embodiment, the extruder may be set in a five temperature zonearrangement, where the first zone is set to a temperature of about 25°C., the second zone is set to a temperature of about 50° C., the thirdzone is set to a temperature of about 95° C., the fourth zone is set toa temperature of about 130° C., and the fifth zone is set to atemperature of about 150° C. In still another embodiment, the extrudermay be set in a six temperature zone arrangement, where the first zoneis set to a temperature of about 90° C., the second zone is set to atemperature of about 100° C., the third zone is set to a temperature ofabout 105° C., the fourth zone is set to a temperature of about 100° C.,the fifth zone is set to a temperature of about 120° C., and the sixthzone is set to a temperature of about 130° C.

The mixture forms a melted plasticized mass in the extruder. A dieassembly is attached to the extruder in an arrangement that permits theplasticized mixture to flow from the extruder exit port into the dieassembly and produces substantial alignment of the protein fibers withinthe plasticized mixture as it flows through the die assembly. The dieassembly may include either a faceplate die or a peripheral die. Thecutter speed is set to size the piece to no more than 5% through a 16mesh screen, and no more than 65% on a ½-inch screen.

One embodiment includes a peripheral die assembly as illustrated andgenerally indicated as 10 in FIGS. 3-5.

As shown in FIGS. 3 and 4, the peripheral die assembly 10 may include adie sleeve 12 having a cylindrical-shaped two-part sleeve die body 17.The sleeve die body 17 may include a rear portion 18 coupled to a frontportion 20 that collectively define an internal chamber 31 incommunication with opposing openings 72, 74. The die sleeve 12 may beadapted to receive a die insert 14 and a die cone 16 for providing thenecessary structural elements to facilitate laminar flow of theplasticized mixture through the peripheral die assembly 10 during theextrusion process.

Additionally, the front portion 20 of the die sleeve 12 may be securedto a die cone 16 adapted to interface with the die insert 14 when thefront portion 20 is secured to the rear portion 18 of the die sleeve 12during assembly of the peripheral die assembly 10. As further shown, therear portion 18 of die sleeve 12 defines a plurality of circular-shapedoutlets 24 along the sleeve body 17 which are adapted to provide aconduit for the egress of the extrudate from the peripheral die assembly10 during the extrusion process. In the alternative, the plurality ofoutlets 24 may have different configurations, such as square,rectangular, scalloped or irregular. As further shown, the rear portion18 of the die sleeve 12 may include a circular flange 37 that surroundsopening 72 and defines a pair of opposing slots 82A and 82B that areused to properly align the die sleeve 12 when engaging the die sleeve 12to the extruder.

As shown in FIG. 5, when the peripheral die assembly 10 is fullyassembled the die insert 14 is disposed within the rear portion 18 ofthe die sleeve 12 which is secured to the front portion 20 of the diesleeve 12 such that the conical side 56 of the die cone 16 is orientedtoward the chamber 31 and encased between the rear and front portions 18and 20. In this orientation, the conical side 56 is operativelyassociated with the front face 27 of the die insert 14. As such, theopposing side walls 50 of each adjacent flow diverter 38, the bottomportion 64 of the die insert 14, and the conical side 56 of the die cone16 collectively define a respective flow channel 40 in communicationwith a respective outlet 24. The flow channel 40 defined between the diesleeve 12, die insert 14 and die cone 16 as described above may betapered on all four sides of the flow channel 40. Accordingly, the flowchannel 40 gradually tapers inwardly on all four sides from the entrance84 to the outlet 24 of each flow channel 40.

Referring to FIG. 5A, an enlarged view illustrating the flow pathway “A”through flow channel 40 is shown. Specifically, flow channel 40communicates with the outlet 24 through opening 70 defined by the dieinsert 14.

During the extrusion process, the peripheral die assembly 10 isoperatively engaged with the extruder and produces a plasticized mixturethat contacts the well 52 defined by the rear face 29 of the die insert14 and flows into the throat 34 and enters the inner space opening 36 asindicated by flow path “A”. The plasticized mixture may enter the innerspace 44 defined by the die insert 14 and enter the entrance 84 of eachtapered flow channel 42. The plasticized mixture then flows through eachflow channel 42 and exits from a respective outlet 24 in a manner thatcauses the substantial alignment of the protein fibers in the extrudateproduced by the peripheral die assembly 10.

The width and height dimensions of the outlet(s) 24 are selected and setprior to extrusion of the mixture to provide the fibrous materialextrudate with the desired dimensions. The width of the outlet(s) 24 maybe set so that the extrudate resembles from a cubic chunk of meat to asteak filet, where widening the width of the outlet(s) 24 decreases thecubic chunk-like nature of the extrudate and increases the filet-likenature of the extrudate. In an exemplary embodiment, the width of theoutlet(s) 24 may be set to a width of from about 10 millimeters to about40 millimeters.

The height dimension of the outlet(s) 24 may be set to provide thedesired thickness of the extrudate. The height of the outlet(s) 24 maybe set to provide a very thin extrudate or a thick extrudate. Forexample, the height of the outlet(s) 24 may be set to from about 1millimeter to about 30 millimeters. In an exemplary embodiment, theheight of the outlet(s) 24 may be set to from about 8 millimeters toabout 16 millimeters.

It is also contemplated that the outlet(s) 24 may be round. The diameterof the outlet(s) 24 may be set to provide the desired thickness of theextrudate. The diameter of the outlet(s) 24 may be set to provide a verythin extrudate or a thick extrudate. For example, the diameter of theoutlet(s) 24 may be set to from about 1 millimeter to about 30millimeters. In an exemplary embodiment, the diameter of the outlet(s)24 may be set to from about 8 millimeters to about 16 millimeters.

Other peripheral die assemblies suitable for use in this invention aredescribed in U.S. Pat. App. No. 60/882,662, which is hereby incorporatedby reference in its entirety.

The extrudate is cut after exiting the die assembly. Suitableapparatuses for cutting the extrudate include flexible knivesmanufactured by Wenger Manufacturing, Inc. (Sabetha, Kans.) andClextral, Inc. (Tampa, Fla.). Typically, the speed of the cuttingapparatus is from about 1000 rpm to about 2500 rpm. In an exemplaryembodiment, the speed of the cutting apparatus is about 1600 rpm.

A dryer, if one is used, generally comprises a plurality of drying zonesin which the air temperature may vary. Generally, the temperature of theair within one or more of the zones will be from about 100° C. to about185° C. Typically, the extrudate is present in the dryer for a timesufficient to provide an extrudate having the desired moisture content.Generally, the extrudate is dried for at least about 5 minutes and moregenerally, for at least about 10 minutes. Alternatively, the extrudatemay be dried at lower temperatures, such as about 70° C., for longerperiods of time. Suitable dryers include those manufactured by WolverineProctor & Schwartz (Merrimac, Mass.), National Drying Machinery Co.(Philadelphia, Pa.), Wenger (Sabetha, Kans.), Clextral (Tampa, Fla.),and Buehler (Lake Bluff, Ill.).

The desired moisture content may vary widely depending on the intendedapplication of the extrudate. Generally speaking, the extruded materialhas a moisture content of from about 6% to about 13% by weight, ifdried, and needs to be hydrated in water until the water is absorbed andthe fibers are separated. If the protein material is not dried or notfully dried, its moisture content is higher, generally from about 16% toabout 30% by weight.

The dried extrudate may further be comminuted to reduce the averageparticle size of the extrudate. Suitable grinding apparatus includehammer mills such as Mikro Hammer Mills manufactured by Hosokawa MicronLtd. (England).

(e) Characterization of the Structured Protein Products

The extrudates produced in I(d) typically comprise the structuredprotein products having protein fibers that are substantially aligned.In the context of this invention “substantially aligned” generallyrefers to the arrangement of protein fibers such that a significantlyhigh percentage of the protein fibers forming the structured proteinproduct are contiguous to each other at less than approximately a 45°angle when viewed in a horizontal plane. Typically, an average of atleast 55% of the protein fibers comprising the structured proteinproduct are substantially aligned. In another embodiment, an average ofat least 60% of the protein fibers comprising the structured proteinproduct are substantially aligned. In a further embodiment, an averageof at least 70% of the protein fibers comprising the structured proteinproduct are substantially aligned. In an additional embodiment, anaverage of at least 80% of the protein fibers comprising the structuredprotein product are substantially aligned. In yet another embodiment, anaverage of at least 90% of the protein fibers comprising the structuredprotein product are substantially aligned. Methods for determining thedegree of protein fiber alignment are known in the art and includevisual determinations based upon micrographic images.

By way of example, FIGS. 1 and 2 depict micrographic images thatillustrate the difference between a structured protein product havingsubstantially aligned protein fibers compared to a protein producthaving protein fibers that are significantly crosshatched. FIG. 1depicts a structured protein product prepared according to I(a)-I(d)having protein fibers that are substantially aligned. Contrastingly,FIG. 2 depicts a protein product containing protein fibers that aresignificantly crosshatched and not substantially aligned. Because theprotein fibers are substantially aligned, as shown in FIG. 1, thestructured protein products utilized in the invention generally have thetexture and consistency of cooked muscle meat. In contrast, extrudateshaving protein fibers that are randomly oriented or crosshatchedgenerally have a texture that is soft or spongy.

In addition to having protein fibers that are substantially aligned, thestructured protein products also typically have shear strengthsubstantially similar to whole meat muscle. In this context of theinvention, the term “shear strength” provides one means to quantify theformation of a sufficient fibrous network to impart whole-muscle liketexture and appearance to the structured protein product. Shear strengthis the maximum force in grams needed to shear through a given sample. Amethod for measuring shear strength is described in Example 1.

Generally speaking, the structured protein products of the inventionwill have average shear strength of at least 1400 grams. In anadditional embodiment, the structured protein products will have averageshear strength of from about 1500 to about 1800 grams. In yet anotherembodiment, the structured protein products will have average shearstrength of from about 1800 to about 2000 grams. In a furtherembodiment, the structured protein products will have average shearstrength of from about 2000 to about 2600 grams. In an additionalembodiment, the structured protein products will have average shearstrength of at least 2200 grams. In a further embodiment, the structuredprotein products will have average shear strength of at least 2300grams. In yet another embodiment, the structured protein products willhave average shear strength of at least 2400 grams. In still anotherembodiment, the structured protein products will have average shearstrength of at least 2500 grams. In a further embodiment, the structuredprotein products will have average shear strength of at least 2600grams.

A means to quantify the size of the protein fibers formed in thestructured protein products may be done by a shred characterizationtest. Shred characterization is a test that generally determines thepercentage of large pieces formed in the structured protein product. Inan indirect manner, percentage of shred characterization provides anadditional means to quantify the degree of protein fiber alignment in astructured protein product. Generally speaking, as the percentage oflarge pieces increases, the degree of protein fibers that are alignedwithin a structured protein product also typically increases.Conversely, as the percentage of large pieces decreases, the degree ofprotein fibers that are aligned within a structured protein product alsotypically decreases.

A method for determining shred characterization is detailed in Example2. The structured protein products of the invention typically have anaverage shred characterization of at least 10% by weight of largepieces. In a further embodiment, the structured protein products have anaverage shred characterization of from about 10% to about 15% by weightof large pieces. In another embodiment, the structured protein productshave an average shred characterization of from about 15% to about 20% byweight of large pieces. In yet another embodiment, the structuredprotein products have an average shred characterization of from about20% to about 25% by weight of large pieces. In another embodiment, theaverage shred characterization is at least 20% by weight, at least 21%by weight, at least 22% by weight, at least 23% by weight, at least 24%by weight, at least 25% by weight, or at least 26% by weight largepieces.

Suitable structured protein products of the invention generally haveprotein fibers that are substantially aligned, have average shearstrength of at least 1400 grams, and have an average shredcharacterization of at least 10% by weight large pieces. More typically,the structured protein products will have protein fibers that are atleast 55% aligned, have average shear strength of at least 1800 grams,and have an average shred characterization of at least 15% by weightlarge pieces. In exemplary embodiment, the structured protein productswill have protein fibers that are at least 55% aligned, have averageshear strength of at least 2000 grams, and have an average shredcharacterization of at least 17% by weight large pieces. In anotherexemplary embodiment, the structured protein products will have proteinfibers that are at least 55% aligned, have average shear strength of atleast 2200 grams, and have an average shred characterization of at least20% by weight large pieces.

(II) Restructured Meat Compositions

The structured protein products are utilized in the invention as acomponent in restructured meat compositions. A restructured meatcomposition may comprise a mixture of animal meat and structured proteinproduct, or it may comprise no meat and primarily structured proteinproduct. The process for producing the restructured meat compositionsgenerally comprises optionally mixing it with animal meat, coloring andhydrating the structured protein product, reducing its particle size,and further processing the composition into a food product comprisingmeat.

(a) Optionally Blend with Animal Meat

The structured protein product may optionally be blended with animalmeat to produce animal meat compositions either before or aftercontacting the structured protein product with the coloring compositiondetailed below. In general, the structured protein product will beblended with animal meat that has a similar particle size.

It is well known in the art to produce mechanically deboned or separatedraw meats using high-pressure machinery that separates bone from animaltissue, by first crushing bone and adhering animal tissue and thenforcing the animal tissue, and not the bone, through a sieve or similarscreening device. The animal tissue in the present invention comprisesmuscle tissue, organ tissue, connective tissue and skin. The processforms an unstructured, paste-like blend of soft animal tissue with abatter-like consistency and is commonly referred to as mechanicallydeboned meat or MDM. This paste-like blend has a particle size of fromabout 0.25 to about 15 millimeters, preferably up to about 5 millimetersand most preferably up to about 3 millimeters.

Although the animal tissue, also known as raw meat, is preferablyprovided in at least substantially frozen form so as to avoid microbialspoilage prior to processing, once the meat is ground, it is notnecessary to freeze it to provide cutability into individual strips orpieces. Unlike meat meal, raw meat has a natural high moisture contentwith a ratio of protein to moisture of from about 1:3.6 to 1:3.7.

The raw meat used in the present invention may be any edible meatsuitable for consumption. The meat may be non-rendered, non-dried, rawmeat, raw meat products, raw meat by-products, and mixtures thereof. Themeat or meat products are comminuted and generally supplied daily in acompletely frozen or at least substantially frozen condition so as toavoid microbial spoilage. Generally the temperature of the comminutedmeat is below about 40° C. (104° F.), preferably below about 10° C. (50°F.) more preferably is from about −4° C. (25° F.) to about 6° C. (43°F.) and most preferably from about −2° C. (28° F.) to about 2° C. (36°F.). While refrigerated or chilled meat may be used, it is generallyimpractical to store large quantities of unfrozen meat for extendedperiods of time at a plant site. The frozen products provide a longerlay time than do the refrigerated or chilled products.

In lieu of frozen comminuted meat, the comminuted meat may be freshlyprepared for the preparation of the restructured meat product, as longas the freshly prepared comminuted meat meets the temperature conditionsof not more than about 40° C. (104° F.).

The moisture content of the raw frozen or unfrozen meat is generally atleast about 50% by weight, and most often from about 60% by weight toabout 75% by weight, based upon the weight of the raw meat. In oneembodiment of the invention, the fat content of the raw frozen orunfrozen meat is at least 2% by weight. Generally the fat content of theraw frozen or unfrozen meat is from about 3% by weight to about 95% byweight. In another embodiment, the fat content of the raw frozen orunfrozen meat is about 20% by weight to about 95% by weight. In otherembodiments of the invention, meat products may be combined to produce ameat composition that has a fat content of from about 15% by weight toabout 30% by weight. In another embodiment, the meat composition mayhave a fat content of less than about 10% by weight and defatted meatproducts may be used.

The frozen or chilled meat may be stored at a temperature of about −18°C. (0.4° F.) to about 0° C. (32° F.). It is generally supplied in 20kilogram blocks. Upon use, the blocks are permitted to thaw up to about10° C. (50° F.), that is, to defrost, but in a tempered environment.Thus, the outer layer of the blocks, for example up to a depth of about¼″, may be defrosted or thawed but still at a temperature of about 0° C.(32° F.), while the remaining inner portion of the blocks, while stillfrozen, are continuing to thaw and thus keeping the outer portion atbelow about 10° C. (50° F.).

A variety of animal meats are suitable for use in the restructured meatcomposition. For example, the meat may be from a farm animal selectedfrom the group consisting of sheep, cattle, goats, pork, bison, andhorses. The animal meat may be from poultry, such as chicken, duck,goose or turkey. Alternatively, the animal meat may be from a gameanimal. Non-limiting examples of suitable game animals include buffalo,deer, elk, moose, reindeer, caribou, antelope, rabbit, squirrel, beaver,muskrat, opossum, raccoon, armadillo, porcupine, alligator, and snake.In a further embodiment, the animal meat may be from a fish orshellfish. Non-limiting examples of suitable fish or fish productsinclude saltwater and freshwater fish, such as, catfish, tuna, salmon,bass, mackerel, pollack, hake, tilapia, cod, grouper, whitefish, bowfin,gar, paddlefish, sturgeon, bream, carp, trout, surimi, walleye,snakehead, and shark. In an exemplary embodiment, the animal meat isfrom beef, pork, or turkey.

Meat includes striated muscle which is skeletal or that which is found,for example, in the tongue, diaphragm, heart, or esophagus, with orwithout accompanying overlying fat and portions of the skin, sinew,nerve and blood vessels which normally accompany the meat flesh.Examples of meat by-products are organs and tissues such as lungs,spleens, kidneys, brain, liver, blood, bone, partially defattedlow-temperature fatty tissues, stomachs, intestines free of theircontents, and the like.

The term “meat by-products” is intended to refer to those non-renderedparts of the carcass of slaughtered animals including but not restrictedto mammals, poultry and the like and including such constituents as areembraced by the term “meat by-products” in the Definitions of FeedIngredients published by the Association of American Feed ControlOfficials, Incorporated.

Typically, the amount of structured protein product in relation to theamount of animal meat in the animal meat compositions can and will varydepending upon the composition's intended use. By way of example, when asignificantly vegetarian composition that has a relatively small degreeof animal flavor is desired, the concentration of animal meat in therestructured meat composition may be about 45%, 40%, 35%, 30%, 25%, 20%,15%, 10%, 5%, 2%, or 0% by weight. Alternatively, when a restructuredmeat composition having a relatively high degree of animal meat flavoris desired, the concentration of animal meat in the restructured meatcomposition may be about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or95% by weight. Consequently, the concentration of hydrated structuredplant protein product in the restructured meat composition may be about5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%,75%, 80%, 85%, 90%, 95%, or 99% by weight. In an exemplary embodiment,the restructured meat composition will generally have from about 40% toabout 60% by weight of the hydrated structured protein product and fromabout 40% to about 60% by weight of animal meat.

It is also envisioned that a variety of meat qualities may be utilizedin the invention. For example, whole meat muscle that is either groundor in chunk or steak form may be utilized. The meat may have a fatcontent that varies widely.

(b) Optionally Blend with Comminuted Vegetable or Comminuted Fruit

The structured protein product may optionally be blended with comminutedvegetable or comminuted fruit to produce restructured meat compositionseither before or after contacting the structured protein product withthe coloring composition detailed below. In general, the structuredprotein product will be blended with comminuted vegetable or comminutedfruit that has a similar particle size.

A variety of vegetables or fruits are suitable for use in therestructured meat composition. Typically, the amount of structuredprotein product in relation to the amount of comminuted vegetable orcomminuted fruit in the restructured meat compositions can and will varydepending upon the composition's intended use. By way of example, theconcentration of comminuted vegetable or comminuted fruit in therestructured meat composition may be about 95%, 90%, 85%, 80%, 75%, 70%,65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 2%, or0% by weight. Consequently, the concentration of hydrated structuredplant protein product in the restructured meat composition may be about5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%,75%, 80%, 85%, 90%, 95%, or 99% by weight. In an exemplary embodiment,the restructured meat composition will generally have from about 40% toabout 60% by weight of the hydrated structured protein product and fromabout 40% to about 60% by weight of comminuted vegetable or comminutedfruit.

(c) Hydrating and Coloring the Structured Protein Product

The structured protein product is generally colored with a coloringcomposition so as to resemble raw meat and/or cooked meat. The coloringcompositions of the invention may comprise thermally unstable pigments,thermally stable pigments, and browning agents. The choice of the typeof pigments and the amount present in the coloring composition can andwill vary depending upon the desired color of the restructured meatcomposition. When the restructured meat composition simulates a“pre-cooked product,” the structured plant product is typicallycontacted with browning agents and/or thermally stable pigments.Alternatively, when the restructured meat composition simulates rawmeat, the structured protein product is generally contacted withthermally unstable red pigments and also with browning agents, and/orthermally stable pigments, such that when the restructured meatcomposition is cooked its appearance changes from a raw meat color tofully cooked color. Suitable thermally unstable red pigments, thermallystable pigments, and browning agents are described below.

The colorant(s) may be mixed with the protein-containing material andother ingredients prior to being fed into the extruder. Alternatively,the colorant(s) may be combined with the protein-containing material andother ingredients after being fed into the extruder. In the presence ofthe heat or the heat and pressure utilized during the extrusion process,some combinations of colorants and protein-containing materials resultin unexpected colors. As an example, when carmine (or lac) is contactedwith the protein-containing material during the extrusion process, thecolor changes from red to violet/purple.

The colorant(s) may be a natural colorant, a combination of naturalcolorants, an artificial colorant, a combination of artificialcolorants, or a combination of natural and artificial colorants.Suitable examples of natural colorants approved for use in food includeannatto (reddish-orange), anthocyanins (red to blue, depends upon pH),beet juice, beta-carotene (orange), beta-APO 8 carotenal (orange), blackcurrant, burnt sugar; canthaxanthin (pink-red), caramel,carmine/carminic acid (bright red), cochineal extract (red), curcumin(yellow-orange); lac (scarlet red), lutein (red-orange); lycopene(orange-red), mixed carotenoids (orange), monascus (red-purple, fromfermented red rice), paprika, red cabbage juice, riboflavin (yellow),saffron, titanium dioxide (white), and turmeric (yellow-orange).Suitable examples of artificial colorants approved for food use in theUnited States include FD&C Red No. 3 (Erythrosine), FD&C Red No. 40(Allure Red), FD&C Yellow No. 5 (Tartrazine), FD&C Yellow No. 6 (SunsetYellow FCF), FD&C Blue No. 1 (Brilliant Blue), FD&C Blue No. 2(Indigotine). Artificial colorants that may be used in other countriesinclude Cl Food Red 3 (Carmoisine), Cl Food Red 7 (Ponceau 4R), Cl FoodRed 9 (Amaranth), Cl Food Yellow 13 (Quinoline Yellow), and Cl Food Blue5 (Patent Blue V). Food colorants may be dyes, which are powders,granules, or liquids that are soluble in water. Alternatively, naturaland artificial food colorants may be lake colors, which are combinationsof dyes and insoluble materials. Lake colors are not oil soluble, butare oil dispersible; they tint by dispersion.

Suitable colorant(s) may be combined with the protein-containingmaterials in a variety of forms. Non-limiting examples include solid,semi-solid, powdered, liquid, and gelatin. The type and concentration ofcolorant(s) utilized may vary depending on the protein-containingmaterials used and the desired color of the colored structured proteinproduct. Typically, the concentration of colorant(s) may range fromabout 0.001% to about 5.0% by weight. In one embodiment, theconcentration of colorant(s) may range from about 0.01% to about 4.0% byweight. In another embodiment, the concentration of colorant(s) mayrange from about 0.05% to about 3.0% by weight. In still anotherembodiment, the concentration of colorant(s) may range from about 0.1%to about 3.0% by weight. In a further embodiment, the concentration ofcolorant(s) may range from about 0.5% to about 2.0% by weight. Inanother embodiment, the concentration of colorant(s) may range fromabout 0.75% to about 1.0% by weight.

A thermally unstable pigment may be used in the coloring composition toprovide the red color of raw uncooked meat. The thermally unstablepigment is typically a food coloring dye or powder having a red colorthat resembles the red coloration of browning meat in its uncooked state(i.e., raw meat). Generally speaking, the thermally unstable pigment isa food coloring dye or powder having a structure that is degraded uponexposure to temperatures effective to cook a structured protein product.In this manner, the pigment is degraded thermally and as such, isineffective to provide substantial coloration to the structured proteinproduct when it is cooked. The thermally unstable pigment is typicallydegraded at temperatures of about 100° C. or greater, more preferably attemperatures of about 75° C. or greater, and most typically attemperatures of about 50° C. or greater. In one embodiment, thethermally unstable pigment is betanin, a red food coloring dye or powderhaving poor thermal stability. Betanin is derived from red beets and istypically prepared from red beet juice or beet powder. The thermallyunstable pigment may be present in the coloring composition from about0.005% to about 30% by dry weight of the coloring composition. When thethermally unstable pigment is betanin, the betanin preferably forms fromabout 0.005% to about 0.5% of the coloring composition by dry weight,and more preferably forms from about 0.01% to about 0.05% of thecoloring composition by dry weight. Alternatively, a beet powder or beetextract preparation containing betanin may be present in the coloringcomposition from about 5% to about 30% of the composition by dry weight,and more preferably from about 10% to about 25% of the coloringcomposition. As an example, the coloring composition could be composedof 0.0087% annatto, 21.68% beet powder, 52.81% dextrose, and 25.43% NFE(all percentages are by weight).

A thermally stable pigment comprised of one or more thermally stablefood coloring dyes may be used in the coloring composition. Suitablethermally stable pigments include those that are effective to provide astructured protein product with coloration resembling browned meat inboth an uncooked state and a cooked state. Suitable thermally stablepigments include caramel food coloring material, and yellow, brown,and/or orange food-coloring agents. A variety of caramel food coloringagents are useful in the present invention and are commerciallyavailable in a powdered form or in a liquid form, including CaramelColor No. 602 (available from the Williamson Company, Louisville, Ky.),and 5440 Caramel Powder D.S. (available from Sensient Colors, Inc., St.Louis, Mo.).

Several types of commercially available yellow/orange food colorings maybe used in the thermally stable pigment. Suitable yellow/orange foodcolors include annatto, turmeric and artificial yellow dyes such as FD&CYellow #5. The amount of thermally stable pigment present in thecoloring composition is from about 0% to about 7% by dry weight of thecoloring composition, and more preferably from about 0.1% to about 3% bydry weight of the coloring composition. The yellow/orange food coloringmaterial, preferably annatto, may constitute from about 0% to about 2%of the coloring composition by dry weight, and preferably is present inabout 0.1% to about 1%, by dry weight of the coloring composition. Thecaramel food coloring material typically constitutes from about 0% toabout 5% by dry weight, and preferably from about 0.5% to about 3%, bydry weight of the coloring composition.

The coloring composition may include browning agents which comprise anamine source and a reducing sugar. As detailed above, the browning agentgenerally causes a protein containing material in which the coloringcomposition is mixed to brown similarly to cook browning meat when theprotein material is cooked. In an alternative embodiment, the browningagent of the coloring composition may also include an amine source. Anamine compound reacts with a reducing sugar to induce browning. Suitableamine sources include a polypeptide material, a hydrolyzed proteinmaterial, or an amino acid material. Without being bound by anyparticular theory, a polypeptide material, hydrolyzed protein, and/oramino acid material is preferably included as an amine source in thebrowning agent to enhance the desired browning. In an exemplaryembodiment, an isolated soy protein is the source of amine groups in thebrowning agent. When included in the coloring composition, the aminesource is generally present in the coloring composition from about 20%to about 55% of the coloring composition by dry weight. An exemplarybrowning agent is a reducing sugar. Suitable reducing sugars aretypically capable of undergoing a Maillard browning reaction in thepresence of compounds containing amine groups to provide the desiredbrowning when a protein containing material is cooked. Representativeexamples of suitable reducing sugars include xylose, arabinose,galactose, fructose, glycealdehyde, mannose, dextrose, lactose andmaltose. In an exemplary embodiment, the reducing sugar is dextrose. Thereducing sugar may be present in the coloring composition from about 25%to about 95% by dry weight of the coloring composition, and preferablyfrom about 30% to about 60% by dry weight of the coloring composition.

In an exemplary embodiment, the coloring composition comprises beetpigment, annatto, caramel coloring, a reducing sugar, and an amino acidsource. In one alternative of this embodiment, the amino acid sourcecomprises peptides comprised of amino acids and secondary amino acids.In another alternative embodiment, the amino acid source is isolated soyprotein.

The coloring composition may further comprise an acidity regulator tomaintain the pH in the optimal range for the colorant. The acidityregulator may be an acidulent. Examples of acidulents that may be addedto food include citric acid, acetic acid (vinegar), tartaric acid, malicacid, fumaric acid, lactic acid, gluconic acid, phosphoric acid, sorbicacid, hydrochloric acid, propionic acid, and benzoic acid. The finalconcentration of the acidulent in a coloring composition may range fromabout 0.001% to about 5% by weight of the coloring composition. Theacidity regulator may also be a pH-raising agent, such as disodiumbiphosphate, sodium carbonate, sodium bicarbonate, sodium hydroxide, andpotassium hydroxide.

The coloring composition of the present invention may be prepared bycombining the components using processes and procedures known to thoseof ordinary skill in the art. The components are typically available ineither a liquid form or a powder form, and often in both forms. Thecomponents can be mixed directly to form the coloring composition, butpreferably the ingredients of the coloring composition are combined inan aqueous solution at a total concentration of about 10% to about 25%by weight, where the aqueous coloring solution can be conveniently addedto a quantity of water for mixing with and coloring a structured proteinproduct.

(d) Addition of Optional Ingredients

The restructured meat compositions may optionally include a variety offlavorings, spices, antioxidants, or other ingredients to impart adesired flavor or texture or to nutritionally enhance the final foodproduct. As will be appreciated by a skilled artisan, the selection ofingredients added to the restructured meat composition can and willdepend upon the food product to be manufactured.

The restructured meat composition may comprise from about 1% to about30% by weight of a fat source to impart flavor. Typically, the fatsource is an animal fat. Suitable animal fats include beef fat, porkfat, poultry fat and lamb fat. In an exemplary embodiment, therestructured meat composition will comprise from about 10% to about 20%by weight of a fat source. In an additional embodiment a plant derivedfat source can be used, non-limiting examples include oils such ascanola oil, cottonseed oil, grape oil, olive oil, peanut oil, palm oil,soybean oil, sunflower oil, vegetable oil, and combinations thereof. Thepercentage by weight of the plant derived fat source can be from about10% to 20%.

The restructured meat compositions may further comprise an antioxidant.The antioxidant may prevent the oxidation of the polyunsaturated fattyacids (e.g., omega-3 fatty acids) in the animal meat, and theantioxidant may also prevent oxidative color changes in the restructuredmeat composition. The antioxidant may be natural or synthetic. Suitableantioxidants include, but are not limited to, ascorbic acid and itssalts, ascorbyl palmitate, ascorbyl stearate, anoxomer,N-acetylcysteine, benzyl isothiocyanate, m-aminobenzoic acid,o-aminobenzoic acid, p-aminobenzoic acid (PABA), butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), caffeic acid,canthaxantin, alpha-carotene, beta-carotene, beta-caraotene,beta-apo-carotenoic acid, carnosol, carvacrol, catechins, cetyl gallate,chlorogenic acid, citric acid and its salts, clove extract, coffee beanextract, p-coumaric acid, 3,4-dihydroxybenzoic acid,N,N′-diphenyl-p-phenylenediamine (DPPD), dilauryl thiodipropionate,distearyl thiodipropionate, 2,6-di-tert-butylphenol, dodecyl gallate,edetic acid, ellagic acid, erythorbic acid, sodium erythorbate,esculetin, esculin, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, ethylgallate, ethyl maltol, ethylenediaminetetraacetic acid (EDTA),eucalyptus extract, eugenol, ferulic acid, flavonoids (e.g., catechin,epicatechin, epicatechin gallate, epigallocatechin (EGC),epigallocatechin gallate (EGCG), polyphenol epigallocatechin-3-gallate),flavones (e.g., apigenin, chrysin, luteolin), flavonols (e.g.,datiscetin, myricetin, daemfero), flavanones, fraxetin, fumaric acid,gallic acid, gentian extract, gluconic acid, glycine, gum guaiacum,hesperetin, alpha-hydroxybenzyl phosphinic acid, hydroxycinammic acid,hydroxyglutaric acid, hydroquinone, N-hydroxysuccinic acid,hydroxytyrosol, hydroxyurea, rice bran extract, lactic acid and itssalts, lecithin, lecithin citrate; R-alpha-lipoic acid, lutein,lycopene, malic acid, maltol, 5-methoxy tryptamine, methyl gallate,monoglyceride citrate; monoisopropyl citrate; morin,beta-naphthoflavone, nordihydroguaiaretic acid (NDGA), octyl gallate,oxalic acid, palmityl citrate, phenothiazine, phosphatidylcholine,phosphoric acid, phosphates, phytic acid, phytylubichromel, pimentoextract, propyl gallate, polyphosphates, quercetin, trans-resveratrol,rosemary extract, rosmarinic acid, sage extract, sesamol, silymarin,sinapic acid, succinic acid, stearyl citrate, syringic acid, tartaricacid, thymol, tocopherols (i.e., alpha-, beta-, gamma- anddelta-tocopherol), tocotrienols (i.e., alpha-, beta-, gamma- anddelta-tocotrienols), tyrosol, vanilic acid,2,6-di-tert-butyl-4-hydroxymethylphenol (i.e., Ionox 100),2,4-(tris-3′,5′-bi-tert-butyl-4′-hydroxybenzyl)-mesitylene (i.e., Ionox330), 2,4,5-trihydroxybutyrophenone, ubiquinone, tertiary butylhydroquinone (TBHQ), thiodipropionic acid, trihydroxy butyrophenone,tryptamine, tyramine, uric acid, vitamin K and derivates, vitamin Q10,wheat germ oil, zeaxanthin, or combinations thereof.

The concentration of an antioxidant in the restructured meat compositionmay range from about 0.0001% to about 20% by weight. In anotherembodiment, the concentration of an antioxidant in the restructured meatcomposition may range from about 0.001% to about 5% by weight. In yetanother embodiment, the concentration of an antioxidant in therestructured meat composition may range from about 0.01% to about 1% byweight.

In an additional embodiment, the restructured meat compositions mayfurther comprise at least one flavoring agent. The flavoring agent maybe natural, or the flavoring agent may be artificial. The flavoringagent may mimic or replace constituents found in lean meat or fattissues, such as, serum proteins, muscle proteins, hydrolyzed animalproteins, tallow, fatty acids, etc. The flavoring agent may provide ananimal meat flavor, a grilled meat flavor, a rare beef flavor, etc. Theflavoring agent may be an animal meat oil, oleoresins or aquaresins ofspice extracts, spice oils, natural smoke solutions, natural smokeextracts, a yeast extract, or shiitake extract. Additional flavoringagents may include onion flavor, garlic flavor, or herb flavors. Therestructured meat composition may further comprise a flavor enhancer.Examples of flavor enhancers that may be used include salt (sodiumchloride), glutamic acid salts (e.g., monosodium glutamate), glycinesalts, guanylic acid salts, inosinic acid salts, 5′-ribonucleotidesalts, hydrolyzed animal proteins, and hydrolyzed vegetable proteins.

The restructured meat composition may optionally include a variety offlavorings. Suitable flavoring agents include animal meat flavor, animalmeat oil, spice extracts, spice oils, natural smoke solutions, naturalsmoke extracts, yeast extracts, sherry, mint, brown sugar, honey. Theflavors and spices may also be available in the form of oleoresins andaquaresins. Other flavoring agents include onion flavor, garlic flavor,or herb flavor. In an alternative embodiment, the flavoring agent may benutty, sweet, or fruity. Non-limiting examples of suitable fruit flavorsinclude apple, apricot, avocado, banana, blackberry, black cherry,blueberry, boysenberry, cantaloupe, cherry, coconut, cranberry, fig,grape, grapefruit, green apple, honeydew, kiwi, lemon, lime, mango,mixed berry, orange, peach, persimmon, pineapple, raspberry, strawberry,and watermelon. The restructured meat compositions may further includeflavor enhancers. Non-limiting examples of suitable flavor enhancersinclude sodium chloride salt, glutamic acid salts, glycine salts,guanylic acid salts, inosinic acid salts, and 5-ribonucleotide salts,yeast extract, shiitake mushroom extract, dried bonito extract, and kelpextract. The restructured meat compositions may also utilize varioussauces and marinades which may be made by fermentation or blendingflavors, spices, oils, water, flavor enhancers, antioxidants,acidulents, preservatives, and sweeteners.

In an additional embodiment, the restructured meat compositions mayfurther comprise a thickening or a gelling agent, such as alginic acidand its salts, agar, carrageenan and its salts, processed Eucheumaseaweed, gums (Gum Arabic, carob bean, locust bean, guar, tragacanth,and xanthan), pectins, sodium carboxymethylcellulose, methylcellulose,and modified starches.

In a further embodiment, the restructured meat compositions may furthercomprise a nutrient such as a vitamin, a mineral, an antioxidant, anomega-3 fatty acid, or an herb. Suitable vitamins include Vitamins A, C,and E, which are also antioxidants, and Vitamins B and D. Examples ofminerals that may be added include the salts of aluminum, ammonium,calcium, magnesium, iron, and potassium. Suitable omega-3 fatty acidsinclude docosahexaenoic acid (DHA), EPA (cicosapentanoic acid) and ALA(alpha-linolenic acid). Herbs that may be added include bay leaves,basil, celery leaves, chervil, chives, cilantro, coriander, cumin, dill,ginger, mace, marjoram, pepper, tumeric, parsley, oregano, tarragon, andthyme.

(III) Food Products

The restructured meat compositions may be processed into a variety offood product having a variety of shapes. When the protein compositionfurther comprises at least one ingredient selected from the groupconsisting of a gelling protein, an animal fat, sodium chloride,phosphates (sodium tripolyphosphate, sodium acid pyrophsphates, hexametaphosphate, etc.), a colorant, a curing agent, an antioxidant, anantimicrobial agent, a flavorant, or mixtures thereof, the product andprocess are completed in a procedure similar to the product and processutilizing only the structured protein products, animal meat, and water.The protein composition is first hydrated with water and shredded toexpose and separate the fibers. When hydration and shredding arecomplete, a colorant is added. The animal meat and water are added andthe contents are mixed until a homogeneous mass is obtained. This isfollowed by the addition of an animal fat, a flavorant, sodium chloride,phosphates, and the gelling protein. In an additional embodiment, sodiumnitrate may be added along with salt and phosphates.

The resulting homogeneous restructured meat product may be formed intostrips, steaks, cutlets, patties, or generally cube-shaped for kabobs,either by hand or by machine. The restructured meat product may beformed into meat sticks. The restructured meat product may also bestuffed into permeable or impermeable casings to form sausages.

The restructured meat product once formed is either cooked, partiallycooked for finishing at a later time or frozen either in an uncookedstate, partially cooked state or cooked state. Cooking includes fryingeither as sautéing or as deep-frying, baking, smoking and impingementcooking and steaming. The fully cooked restructured meat product may befurther sliced, shredded, or ground.

Further, the restructured meat product may be subjected to fermentation.Meat products are fermented by adjusting the pH of the meat product tobetween about 4.0 to about 5.2. Fermentation is accomplished by theaddition of a lactic acid culture. Acidification may also be performedby direct acidification using citric acid, lactic acid, glucono deltalactone, and mixtures thereof.

The restructured meat product (before drying, partially dried, dried,cooked or uncooked) may be packaged as is. Further processing of therestructured meat product (before drying, partially dried, dried, cookedor uncooked) may be shock-frozen, for example in a freeze tunnel, andsubsequent automatic portion packaging in containers of a suitable type,for example, plastic pouches or the like. Said type of furtherprocessing and packaging is suitable if the product is intended forfast-food outlets or for food service applications, where the product isusually deep-fried or baked before consumption.

Alternatively, after the formation of the restructured meat product(before drying, partially dried, dried, cooked or uncooked), it is alsopossible to spray the surface of the product with carbohydrate solutionsor related substances in order to obtain uniform browning during deepfrying or baking. Subsequently, the product can now be shock frozen andsold portion packed (i.e. in pouches). The restructured meat product canalso be baked or processed in a convection oven by the consumer, insteadof deep frying. Further, the restructured meat product also can bebreaded prior to or after cooking, or coated with another type ofcoating. Additionally, the restructured meat product can be retortcooked in order to kill any microbes that might be present.

The restructured meat product either cooked or uncooked may also bepacked and sealed in cans in a conventional manner and employingconventional sealing procedures. Normally, the cans at this stage aremaintained at a temperature of between 65° C. and 77° C. and are carriedto a retort or cooking stage as quickly as possible to prevent therebeing any risk of microbiological spoilage during the time betweencanning and sterilization during the retort or cooking stage. Therestructured meat stuffed in impermeable casings designed for retortcooking may be cooked in the retort cooker to make a shelf stablesausage.

In order to ensure that the restructured meat product, once formed, hasthe texture of intact muscles, it is necessary that at least about 75weight % of the protein composition contains at least about 15 weight %of large pieces comprised of vegetable protein fibers at least about 4centimeters long, vegetable protein strands at least about 3 centimeterslong, and vegetable protein chunks at least about 2 centimeters long andthat at least about 75 weight % of the protein composition has a shearstrength of at least about 1400 grams.

A vegetable product may be prepared by a process of combining a proteincomposition, preferably a hydrated and shredded soy protein composition;wherein about 75 weight % of the protein composition is comprised of atleast about 15 weight % of fragments comprised of protein fibers atleast about 4 centimeters long, protein strands at least about 3centimeters long, and protein chunks at least about 2 centimeters long;and wherein at least about 75 weight % of the protein composition has ashear strength of at least about 1400 grams; with

a comminuted vegetable; and

mixing the preferred hydrated and shredded soy protein composition andthe comminuted vegetable to produce a homogeneous, fibrous andstructured vegetable product having protein fibers that aresubstantially aligned.

Examples of vegetable products prepared by the above process arevegetarian food products including vegetarian patties, vegetarian hotdogs, vegetarian sausages, and vegetarian crumbles. Another example of avegetarian food product is cheeses that are extended with the hydratedand shredded protein composition.

A fruit product may be prepared by combining a protein composition,preferably a hydrated and shredded soy protein composition; whereinabout 75 weight % of the protein composition is comprised of at leastabout 15 weight % of fragments comprised of protein fibers at leastabout 4 centimeters long, protein strands at least about 3 centimeterslong, and protein chunks at least about 2 centimeters long; and whereinat least about 75 weight % of the protein composition has a shearstrength of at least about 1400 grams; with a comminuted fruit; andmixing the preferred hydrated and shredded soy protein composition andthe comminuted fruit to produce a homogeneous, fibrous and structuredfruit product having protein fibers that are substantially aligned.

Examples of fruit products prepared by the above process are snack foodproducts including fruit rollups, cereals, and fruit crumbles.

DEFINITIONS

The term “animal meat” as used herein refers to the flesh, whole meatmuscle, or parts thereof derived from an animal.

The term “comminuted fruit” as used herein refers to a puree of a singlefruit or a mixture of a puree of more than one fruit.

The term “comminuted meat” as used herein refers to a meat paste that isrecovered from an animal carcass. The meat, on or off the bone is forcedthrough a deboning device such that meat is separated from the bone andreduced in size.

The term “comminuted vegetable” as used herein refers to a puree of asingle vegetable or a mixture of a puree of more than one vegetable.

The term “extrudate” as used herein refers to the product of extrusion.In this context, the plant protein products comprising protein fibersthat are substantially aligned may be extrudates in some embodiments.

The term “fiber” as used herein refers to a plant protein product havinga size of approximately 4 centimeters in length and 0.2 centimeters inwidth after the shred characterization test detailed in Example 2 isperformed. In this context, the term “fiber” does not include thenutrient class of fibers, such as soybean cotyledon fibers, and alsodoes not refer to the structural formation of substantially alignedprotein fibers comprising the plant protein products.

The term “gluten” as used herein refers to a protein fraction in cerealgrain flour, such as wheat, that possesses a high content of protein aswell as unique structural and adhesive properties.

The term “gluten free starch” as used herein refers to various starchproducts such as modified tapioca starch. Gluten free or substantiallygluten free starches are made from wheat, corn, and tapioca basedstarches. They are gluten free because they do not contain the glutenfrom wheat, oats, rye or barley.

The term “hydration test” as used herein measures the amount of time inminutes necessary to hydrate a known amount of the protein composition.

The term “large piece” as used herein is the manner in which a coloredor uncolored structured plant protein product's shred percentage ischaracterized. The determination of shred characterization is detailedin Example 2.

The term “mechanically deboned meat (MDM)” as used herein refers to ameat paste that is recovered from beef, pork and chicken bones usingcommercially available equipment. MDM is a comminuted product that isdevoid of the natural fibrous texture found in intact muscles.

The term “moisture content” as used herein refers to the amount ofmoisture in a material. The moisture content of a material can bedetermined by A.O.C.S. (American Oil Chemists Society) Method Ba 2a-38(1997), which is incorporated herein by reference in its entirety.

The term “protein content,” as for example, soy protein content as usedherein, refers to the relative protein content of a material asascertained by A.O.C.S. (American Oil Chemists Society) Official MethodsBc 4-91(1997), Aa 5-91(1997), or Ba 4d-90(1997), each incorporatedherein by reference in their entirety, which determine the totalnitrogen content of a material sample as ammonia, and the proteincontent as 6.25 times the total nitrogen content of the sample.

The term “protein fiber” as used herein refers to the individualcontinuous filaments or discrete elongated pieces of varying lengthsthat together define the structure of the plant protein products of theinvention. Additionally, because both the colored and uncoloredstructured plant protein products of the invention have protein fibersthat are substantially aligned, the arrangement of the protein fibersimpart the texture of whole meat muscle to the colored and uncoloredstructured plant protein products.

The term “shear strength” as used herein measures the ability of atextured protein to form a fibrous network with a strength high enoughto impart meat-like texture and appearance to a formed product. Shearstrength is measured in grams.

The term “simulated” as used herein refers to an animal meat compositionthat contains no animal meat.

The term “soy cotyledon fiber” as used herein refers to thepolysaccharide portion of soy cotyledons containing at least about 70%dietary fiber. Soy cotyledon fiber typically contains some minor amountsof soy protein, but may also be 100% fiber. Soy cotyledon fiber, as usedherein, does not refer to, or include, soy hull fiber. Generally, soycotyledon fiber is formed from soybeans by removing the hull and germ ofthe soybean, flaking or grinding the cotyledon and removing oil from theflaked or ground cotyledon, and separating the soy cotyledon fiber fromthe soy material and carbohydrates of the cotyledon.

The term “soy protein concentrate” as used herein is a soy materialhaving a protein content of from about 65% to less than about 90% soyprotein on a moisture-free basis. Soy protein concentrate also containssoy cotyledon fiber, typically from about 3.5% up to about 20% soycotyledon fiber by weight on a moisture-free basis. A soy proteinconcentrate is formed from soybeans by removing the hull and germ of thesoybean, flaking or grinding the cotyledon and removing oil from theflaked or ground cotyledon, and separating the soy protein and soycotyledon fiber from the soluble carbohydrates of the cotyledon.

The term “soy flour” as used herein, refers to a comminuted form ofdefatted soybean material, preferably containing less than about 1% oil,formed of particles having a size such that the particles can passthrough a No. 100 mesh (U.S. Standard) screen. The soy cake, chips,flakes, meal, or mixture of the materials are comminuted into soy flourusing conventional soy grinding processes. Soy flour has a soy proteincontent of about 49% to about 65% on a moisture free basis. Preferablythe flour is very finely ground, most preferably so that less than about1% of the flour is retained on a 300 mesh (U.S. Standard) screen.

The term “soy protein isolate” as used herein is a soy material having aprotein content of at least about 90% soy protein on a moisture freebasis. A soy protein isolate is formed from soybeans by removing thehull and germ of the soybean from the cotyledon, flaking or grinding thecotyledon and removing oil from the flaked or ground cotyledon,separating the soy protein and carbohydrates of the cotyledon from thecotyledon fiber, and subsequently separating the soy protein from thecarbohydrates.

The term “strand” as used herein refers to a plant protein producthaving a size of approximately 2.5 to about 4 centimeters in length andgreater than approximately 0.2 centimeter in width after the shredcharacterization test detailed in Example 2 is performed.

The term “starch” as used herein refers to starches derived from anynative source. Typically sources for starch are cereals, tubers, roots,legumes, and fruits.

The term “weight on a moisture free basis” as used herein refers to theweight of a material after it has been dried to completely remove allmoisture, e.g. the moisture content of the material is 0%. Specifically,the weight on a moisture free basis of a material can be obtained byweighing the material after the material has been placed in a 45° C.oven until the material reaches a constant weight.

The term “wheat flour” as used herein refers to flour obtained from themilling of wheat. Generally speaking, the particle size of wheat flouris from about 14 to about 120 μm.

The following examples are included to demonstrate preferred embodimentsof the invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples that follow representtechniques discovered by the inventors to function well in the practiceof the invention. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments that are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention, therefore all matter set forth or shown in the accompanyingdrawings is to be interpreted as illustrative and not in a limitingsense.

EXAMPLES

Examples 1-105 illustrate various embodiments of the invention.

Example 1 Determination of Shear Strength

Shear strength of a sample is measured in grams and may be determined bythe following procedure. Weigh a sample of the structured proteinproduct and place it in a heat sealable pouch and hydrate the samplewith approximately three times the sample weight of room temperature tapwater. Evacuate the pouch to a pressure of about 0.01 Bar and seal thepouch. Permit the sample to hydrate for about 12 to about 24 hours.Remove the hydrated sample and place it on the texture analyzer baseplate oriented so that a knife from the texture analyzer will cutthrough the diameter of the sample. Further, the sample should beoriented under the texture analyzer knife such that the knife cutsperpendicular to the long axis of the textured piece. A suitable knifeused to cut the extrudate is a model TA-45, incisor blade manufacturedby Texture Technologies (USA). A suitable texture analyzer to performthis test is a model TA, TXT2 manufactured by Stable Micro Systems Ltd.(England) equipped with a 25, 50, or 100 kilogram load. Within thecontext of this test, shear strength is the maximum force in gramsneeded to shear through the sample.

Example 2 Determination of Shred Characterization

A procedure for determining shred characterization may be performed asfollows. Weigh about 150 grams of a structured protein product usingwhole pieces only. Place the sample into a heat-sealable plastic bag andadd about 450 grams of water at 25° C. Vacuum seal the bag at about 150mm Hg and allow the contents to hydrate for about 60 minutes. Place thehydrated sample in the bowl of a Kitchen Aid mixer model KM14G0 equippedwith a single blade paddle and mix the contents at 130 rpm for twominutes. Scrape the paddle and the sides of the bowl, returning thescrapings to the bottom of the bowl. Repeat the mixing and scraping twotimes. Remove ˜200 g of the mixture from the bowl. Separate that mixturesuch that all fibers or long strands longer that 2.5 cm are segregatedfrom the shredded mixture. Weigh the population of fibers sorted fromthe shredded mixture, divide this weight by the starting weight (e.g.˜200 g), and multiply this value by 100. This determines the percentageof large pieces in the sample. If the resulting value is below 15%, orabove 20%, the test is complete. If the value is between 15% and 20%,then weigh out another ˜200 g from the bowl, separate the fibers or longstrands longer that 2.5 cm from the shredded mixture, and perform thecalculations again.

Example 3 Production of Plant Protein Products

The following extrusion process may be used to prepare the coloredstructured plant protein products of the invention. Added to a dry blendmixing vessel are the following: 1000 kilograms (kg) Supro 620 (soyisolate), 440 kg wheat gluten, 236 kg wheat starch, 34 kg soy cotyledonfiber, 8 kg dicalcium phosphate, and 2 kg L-cysteine. The contents aremixed to form a dry blended soy protein mixture. The dry blend is thentransferred to a hopper from which the dry blend is introduced into apreconditioner along with 480 kg of water to form a conditioned soyprotein pre-mixture. The conditioned soy protein pre-mixture is then fedto a twin-screw extrusion apparatus at a rate of not more than 25kg/minute. The extrusion apparatus comprises five temperature controlzones, with the protein mixture being controlled to a temperature offrom about 25° C. in the first zone, about 50° C. in the second zone,about 95° C. in the third zone, about 130° C. in the fourth zone, andabout 150° C. in the fifth zone. The extrusion mass is subjected to apressure of at least about 400 psig in the first zone up to about 1500psig in the fifth zone. Water, 60 kg, is injected into the extruderbarrel, via one or more injection jets in communication with a heatingzone.

A die assembly is attached to the extruder in an arrangement thatpermits the plasticized mixture to flow from the extruder exit port intothe die assembly and produces substantial alignment of the proteinfibers within the plasticized mixture as it flows through the dieassembly.

As the extrudate containing protein fibers that are substantiallyaligned exits the die assembly, it is cut with knives and the cut massis then dried to a moisture content of about 10% by weight. Once dry, aportion of the cut mass is sized into small pieces and larger pieces. Atotal of 25 pieces are obtained for each size. These pieces are thenmeasured and tabulated in Table IV.

TABLE IV Sample Small Pieces Large Pieces Number L (mm) W (mm) L (mm) W(mm) 1 11 10 16 11 2 10 6 16 13 3 8 8 22 11 4 11 8 19 11 5 14 9 17 11 610 8 20 13 7 14 4 15 10 8 8 6 21 12 9 10 8 19 12 10 11 8 12 12 11 13 815 10 12 19 9 17 9 13 12 9 11 10 14 14 6.5 14 10 15 10 7 14 10 16 10 717 12 17 10 6 15 13 18 12 8 14 14 19 10 7 19 12 20 9 6 18 10 21 10 8 1412 22 9 5 19 12 23 10 7 12 11 24 11 9 16 10 25 9 8 16 9 Avg 11.0 7.4 Avg16.3 11.2 Std. Dev 2.3 1.4 Std. Dev. 2.8 1.3 Max 19.0 10.0 Max 22.0 14.0Min 8.0 4.0 Min 11.0 9.0

Examples 4-94 Production of Plant Protein Products

Examples 4-94 are repeats of Example 3. Table V below delineates theanalyses of Examples 3-94.

TABLE V Example % Large Shear Density Number# Pieces Strength (g)Hydration (g/cc) 3 30.2 2150 80 0.27 4 24.2 2366 80 0.24 5 29.4 2341 600.30 6 26.0 2142 70 0.29 7 27.1 2291 70 0.28 8 32.7 2442 70 0.23 9 17.42668 70 0.27 10 26.1 2511 90 0.26 11 21.1 2260 80 0.28 12 22.3 2421 800.24 13 12.9 2490 75 0.28 14 22.4 2438 104 0.28 15 7.8 59 81 0.30 16 7.3675 83 0.28 17 9.3 553 100 0.24 18 7.3 226 90 0.23 19 3.5 412 72 0.24 200.0 055 100 0.23 21 2.6 511 75 0.25 22 2.7 168 100 0.25 23 2.0 207 1020.25 24 7.7 247 62 0.29 25 1.2 51 73 0.28 26 0.2 164 63 0.27 27 6.6 96668 0.28 28 4.9 164 50 0.31 29 5.0 812 58 0.28 30 9.6 108 60 0.31 31 5.8864 70 0.27 32 6.5 473 58 0.25 33 0.7 879 65 0.28 34 5.4 688 70 0.29 350.3 038 74 0.26 36 9.3 074 73 0.28 37 1.5 937 70 0.39 38 2.5 462 77 0.4039 0.1 051 66 0.28 40 7.9 384 54 0.31 41 8.1 064 58 0.28 42 9.2 158 600.27 43 0.0 834 58 0.28 44 6.8 202 58 0.28 45 2.8 363 57 0.26 46 3.9 36157 0.28 47 6.9 293 103 0.25 48 6.3 205 73 0.28 49 9.0 286 53 0.29 50 2.6206 63 0.25 51 0.5 125 63 0.31 52 5.5 290 55 0.29 53 8.2 274 55 0.26 541.5 205 42 0.33 55 1.3 185 55 0.31 56 1.8 969 40 0.30 57 9.1 028 55 0.3158 7.2 598 63 0.37 59 8.3 869 60 0.31 60 9.7 044 50 0.29 61 7.6 216 520.28 62 5.0 001 53 0.28 63 8.1 096 45 0.27 64 9.0 796 53 0.27 65 0.0 92451 0.27 66 3.7 295 51 0.28 67 7.4 259 50 0.29 68 9.2 204 43 0.28 69 5.3059 38 0.31 70 6.1 284 70 0.32 71 3.6 085 70 0.30 72 5.6 279 44 0.28 733.7 170 44 0.32 74 1.2 128 49 0.29 75 2.4 068 50 0.29 76 0.1 939 40 0.3077 8.7 592 50 0.30 78 9.6 812 68 0.28 79 5.2 848 64 0.28 80 3.6 973 700.30 81 3.7 078 66 0.36 82 5.6 940 44 0.31 83 8.5 339 33 0.29 84 0.2 36650 0.24 85 8.1 425 40 0.29 86 9.6 122 59 0.27 87 7.5 193 56 0.16 88 1.1186 56 0.28 89 2.4 061 56 0.27 90 1.3 143 50 0.27 91 4.4 108 54 0.26 929.9 101 53 0.30 93 2.3 551 55 0.25 94 4.3 164 57 0.28 1^(st) Quartile2.6 045 53 0.27 Median 6.5 164 60 0.28 1^(st) Quartile 0.2 291 70 0.30Mean 6.6 156 63 0.28

Example 95 Production of Protein Composition

Added to a mixing vessel are 3625 grams of tap water at about 10° C.(50° F.) and while stirring 1160 grams of a dried, low moisture (about7% to about 12%) soy protein composition, identified as FXP MO339,available from Solae, LLC, St. Louis, Mo. comprising a soy proteinisolate, soy cotyledon fiber, wheat gluten and starch is added until thesoy protein composition is hydrated and the fibers are separated. Addedto the mixer are 5216 grams of comminuted meat of mechanically debonedchicken having a moisture content of at least about 50%. Themechanically deboned chicken is at a temperature of from about 2° C.(36° F.) to about 4° C. (39° F.). The contents are mixed until ahomogeneous restructured meat product is obtained. The restructured meatproduct is transferred to a Hollymatic forming machine where therestructured meat product is formed into steaks or cutlets that are thenfrozen.

The procedure of Example 3 is repeated, except that 1500 grams of anon-dried low moisture (about 28-about 35%) soy protein compositioncomprising a soy protein isolate, soy cotyledon fiber, wheat gluten andstarch is hydrated with 3175 grams water. The restructured meat productis transferred to a stuffing machine where the restructured meat productis stuffed into impermeable casings, which are then frozen. Stuffingmachines are available from various commercial manufacturers including,but not limited to, HITEC Food Equipment, Inc., located in Elk GroveVillage, Ill., Townsend Engineering Co., located in Des Moines, Iowa,Robert Reiser & Co., Inc., located in Canton, Mass., and Handtmann,Inc., located in Buffalo Grove, Ill.

Example 97

Added to a first mixing vessel are 2127 grams of tap water at about 12°C. (54° F.) and while stirring 1000 grams of a dried, low moisture(about 7% to about 12%) soy protein composition is added until the soyprotein composition is hydrated and the fibers are separated. Caramelcoloring, 43 grams, is then added to the hydrated soy proteincomposition. At about 2° C. (36° F.), 4500 grams of a comminuted meat ofmechanically deboned chicken having a moisture content of about 50% isadded. Then added are 100 grams sodium chloride and 30 grams of sodiumtripolyphosphate to extract/solubilize myofibriller protein in thecomminuted meat for binding. As mixing is continued, 500 grams beef fatand 100 grams beef flavor are added and mixing is continued. In a secondmixing vessel, a gelling protein of 600 grams of Supro® 620 is hydratedin 1000 grams water and is added to the first mixing vessel. Thecontents are mixed until a homogeneous restructured meat product isobtained. The restructured meat product is transferred to a Hollymatic(Hollymatic Corp., Park Forest Ill.) forming machine where therestructured meat product is formed into patties, which are then frozen.

Example 98

Added to a mixing vessel are 3000 grams of tap water at about 10° C.(50° F.) and while stirring 1500 grams of a soy protein extrudateprepared from Supro® 620 is added until the soy protein composition ishydrated and the fibers are separated by shredding. Added to the mixerare 5000 grams of a comminuted meat of mechanically deboned chickenhaving a moisture content of at least about 50%. The mechanicallydeboned chicken is at a temperature of from about 2° C. (36° F.) toabout 4° C. (39° F.). The contents are mixed until a homogeneousrestructured meat product is obtained. The restructured meat product istransferred to a Hollymatic forming machine where the restructured meatproduct is formed into steaks or cutlets that are then frozen.

Example 99

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate, riceflour, and a gluten free starch.

Example 100

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate andrice flour.

Example 101

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate and agluten free starch.

Example 102

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate, wheatflour and starch.

Example 103

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate and soycotyledon fiber.

Example 104

The procedure of Example 98 is repeated except that the hydrated andshredded soy protein composition comprises a soy protein isolate, soycotyledon fiber, and wheat gluten.

Example 105

Added to a mixing vessel are 3383 grams of tap water at about 10° C.(50° F.) and while stirring 1208 grams of a dried, low moisture (about7% to about 12%) soy protein extrudate, identified as SUPROMAX® 5050, isadded until the soy protein extrudate is hydrated and the fibers areseparated by shredding. Added to the mixer are 3340 grams of acomminuted meat of mechanically deboned chicken having a moisturecontent of at least about 50% and 3383 grams of beef of a ½ inch grindhaving a fat content of about 10%. The mechanically deboned chicken andthe beef grind are at a temperature of from about 2° C. (36° F.) toabout 4° C. (39° F.). Also added are various colorants and flavorants ofsalt, erythorbate, sodium nitrite, dextrose, cracked black pepper,nutmeg, mace, granulated garlic, coriander, red pepper, and a rehydratedLHP starter culture. The contents are mixed until a homogeneousrestructured meat product is obtained. The restructured meat product isthen formed into meat sticks.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thedescription. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

What is claimed is:
 1. A structured protein product made from at leastone ingredient containing protein, wherein the structured proteinproduct comprises protein fibers that are substantially aligned andwherein the arrangement of protein fibers are such that an average of atleast 55% of the protein fibers forming the structured protein productare contiguous to each other at less than a 45° angle when viewed in ahorizontal plane, and wherein said structured protein product is furthercharacterized by average shear strength of at least 1400 grams.
 2. Astructured protein product according to claim 1, wherein the arrangementof protein fibers are such that at least 55% of the protein fibersforming the structured protein product are contiguous to each other atless than a 45° angle when viewed in a horizontal plane.
 3. A structuredprotein product according to claim 2, wherein the arrangement of proteinfibers are such that at least 55% of the protein fibers forming thestructured protein product are contiguous to each other at less than a45° angle when viewed in a horizontal plane, and wherein said structuredprotein product is further characterized by a shear strength of at least1400 grams.
 4. A structured protein composition according to claim 1,which has average shear strength of 1500 to 1800 grams, or 1800 to 2000grams, or 2000 to 2600 grams.
 5. A structured protein compositionaccording to claim 1, which has a shear strength of 1500 to 1800 grams,or 1800 to 2000 grams, or 2000 to 2600 grams.
 6. The structured proteinproduct according to claim 1, wherein said structured protein product isfurther characterized by an average shred characterization of at least10% by weight of large pieces.
 7. The structured protein productaccording to claim 6, wherein said structured protein product is furthercharacterized by shred characterization of at least 10% by weight oflarge pieces.
 8. The structured protein product according to claim 6,wherein the product has an average shred characterization of from 15% to20% by weight of large pieces or 20% to 25% by weight of large pieces.9. The structured protein product according to claim 7, wherein theproduct has a shred characterization of from 15% to 20% by weight oflarge pieces or 20% to 25% by weight of large pieces.
 10. The structuredprotein product according to claim 1, wherein the arrangement of proteinfibers is such that at least 55% are aligned, have an average shearstrength of at least 1800 grams, and have an average shredcharacterization of at least 15% by weight large pieces.
 11. Thestructured protein product according to claim 10, wherein thearrangement of protein fibers is such that at least 55% are aligned,have a shear strength of at least 1800 grams, and have a shredcharacterization of at least 15% by weight large pieces.
 12. Thestructured protein product according to claim 1, wherein the arrangementof protein fibers is such that at least 55% are aligned, have an averageshear strength of at least 2200 grams, and have an average shredcharacterization of at least 20% by weight large pieces.
 13. Thestructured protein product according to claim 12, wherein thearrangement of protein fibers is such that at least 55% are aligned,have a shear strength of at least 2200 grams, and have a shredcharacterization of at least 20% by weight large pieces.
 14. Thestructured protein product according to claim 1, wherein said ingredientcontaining protein is derived from a plant source or animal source. 15.The structured protein product according to claim 14, wherein said plantsource is selected from the group consisting of legumes, corn, peas,canola, sunflowers, sorghum, rice, amaranth, potato, tapioca, arrowroot,canna, lupin, rape, wheat, oats, rye, barley, or mixtures thereof. 16.The structured protein product according to claim 14, wherein said plantsource is soybeans.
 17. The structured protein product according toclaim 16, wherein said ingredient containing protein is selected fromthe group consisting of a soy protein isolate, a soy proteinconcentrate, a soy protein flour, or mixtures thereof.
 18. Thestructured protein product according to claim 14, wherein said plantsource is wheat.
 19. The structured protein product according to claim1, further comprising one or more ingredients selected from the groupconsisting of a starch, flour, gluten, dietary fiber, or mixturesthereof.
 20. The structured protein product according to claim 19,wherein said structured protein product comprises: (a) from 45% to 65%soy protein on a dry matter basis; (b) from 20% to 30% wheat gluten on adry matter basis; (c) from 10% to 15% wheat starch on a dry matterbasis; and (d) from 1% to 5% fiber on a dry matter basis.
 21. Thestructured protein product according to claim 1, wherein said structuredprotein product is an extrudate.
 22. The structured protein productaccording to claim 1 further containing antioxidants, antimicrobialagents or a combination thereof.
 23. The structured protein productaccording to claim 1 further comprising a colorant composition.
 24. Useof the structured protein product according to claim 1 for preparing arestructured meat composition.
 25. Use according to claim 24, whereinthe restructured meat composition also comprises animal meat orcomminuted vegetable or comminuted fruit.